Drink Water!
Water is your body’s principle chemical component and makes up 60% of your body weight. Water flushes toxins out of vital organs, carries nutrients to cells and provides a moist environment for ear, nose, and throat tissues. Lack of water can lead to dehydration, and even mild dehydration (as low as 1-2% loss of normal water volume) can drain your energy and make you tired.
Institute of Medicine